JPH09211223A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce the damage of the optical element and optical fiber in the optical module by precoating an optical path with a light transmitting resin and then sealing the resin at a specified temp. SOLUTION: A light emitting element, a light receiving element, an optical waveguide and an optical fiber are optically connected in the optical module, an optical path is precoated with a light transmitting resin, and the resin is sealed at 100-130 deg.C. An epoxy resin shown in formula I, a curing agent shown in formula II and a curing accelerator shown in formula II are used as the essential components, the resin further contains 50-95wt.% silica filler, and the resin is sealed at 100-130 deg.C. In formula III, X1 , X2 and X3 are the atom or atomic group selected from >=1C org. group, hydrogen atom, hydroxyl and halogen atom and can be the same or different.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel optical module encapsulating resin composition and an optical module using the same.

[0002]

2. Description of the Related Art With the progress of optical communication technology in recent years, construction of an optical fiber network up to home is being promoted. For this purpose, a low-priced optical module is indispensable, and a low-priced encapsulation technology that replaces metal encapsulation and ceramic encapsulation is desired. In the semiconductor encapsulation process, low-voltage transfer mold type resin encapsulation is used in which a resin is put into a mold heated to about 170 ° C. to encapsulate the element (Japanese Patent Laid-Open No. 5-54865). However, if this sealing technique is applied to an optical module, problems such as deterioration of the optical fiber coating due to heating and distortion of fixing the optical element occur. Therefore, it is desirable to seal at a temperature as low as possible.

[0003]

DISCLOSURE OF THE INVENTION The object of the present invention is 130
An object of the present invention is to provide an optical module made of a sealing resin which can be sealed at a temperature of 100 ° C. or lower and 100 ° C. or higher and has a small heat shrinkage rate.

[0004]

In order to achieve the above object, the present invention uses the following technical means.
That is, the first means is an optical module in which a light emitting element, a light receiving element, an optical waveguide, and an optical fiber are arranged so as to be optically coupled, and the optical path is pre-coated with a light-transmissive resin and then sealed with a resin. An optical module, wherein the stop molding is performed at a temperature of 130 ° C. or lower and 100 ° C. or higher.

The second means is to use an epoxy resin represented by Chemical formula 7, a curing agent represented by Chemical formula 8 and a curing accelerator represented by the general formula 9 as essential components, and a silica filler in an amount of 50 to 95.
Contains 100% by weight, and resin encapsulation molding is below 130 ° C 100
An optical module which is performed at a temperature of ℃ or more.

[0006]

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[0007]

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[0008]

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A third means is to use an epoxy resin represented by Chemical formula 10, a curing agent represented by Chemical formula 11 and a curing accelerator represented by the general formula 12 as essential components, and a silica filler in an amount of 50 to 50%.
Contains 95% by weight, and resin encapsulation molding is 130 ° C or less 1
An optical module which is performed at a temperature of 00 ° C. or higher.

[0010]

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[0011]

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[0012]

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The curing temperature in the present invention is 100 ° C. when the temperature of 130 ° C. or higher causes deterioration of the coating of the optical fiber.
Below, the curing reaction is insufficient.

The light-transmitting resin for precoating the optical path in the present invention varies depending on the wavelength used for optical communication,
Any material can be used as long as it is transparent at that wavelength and has a heat resistance of 130 ° C. or higher. Polyimide, fluorinated polyimide, polymethylmethacrylate, polyurethane, epoxy resin, etc. are available. Alternatively, a photocurable resin may be used.

In the present invention, the naphthalene type polyfunctional epoxy resin represented by Chemical formula 13, the trishydroxyphenylmethane type polyfunctional epoxy resin represented by Chemical formula 14, the trishydroxyphenylmethane type polyfunctional phenol curing agent represented by Chemical formula 3, and triphenylphosphine are used. By using the fin and its derivative curing accelerator as the base resin of the encapsulating resin composition, 1
Molding at low temperatures of 00 to 130 ° C is possible. Also,
In these resin moldings, when molded at a normal molding temperature, the glass transition temperature becomes high, so the amount of heat shrinkage decreases, and the amount of strain can be significantly reduced.

[0016]

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[0017]

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Others The epoxy resin used in the encapsulating resin composition of the present invention can be any one that can raise the glass transition temperature to the molding temperature or higher and has a plurality of epoxy groups in one molecule. It can be anything. Examples of such an epoxy resin include bisphenol A, F or S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, or a bifunctional or higher functional group having a biphenyl skeleton, a naphthalene skeleton, or a dicyclopentadiene skeleton in the molecule. Examples thereof include epoxy resins, alicyclic epoxy resins, and epoxy resins obtained by brominated the above epoxy resins. In the present invention, they are used alone or as a mixture of several kinds.

In the present invention, the curing agent having a phenolic hydroxyl group may be any one as long as it has a plurality of phenolic hydroxyl groups in one molecule. As such a curing agent, bisphenol A, F or S, phenol novolac, cresol novolac, or biphenol having a biphenyl skeleton in the molecule, those having a naphthalene skeleton, those having a dicyclopentadiene skeleton, and polymers of the above resins , Or a mixture of several types is used. These are used depending on various properties such as resin moldability such as reactivity and fluidity, and moisture absorption rate of cured product and mechanical properties.

In the encapsulating resin composition used in the present invention, triphenylphosphine represented by Chemical formula 15 and its derivative must be added as a curing accelerator for promoting the curing reaction at 130 ° C. or lower and 100 ° C. or higher. is there.

[0021]

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Examples of such curing accelerators include triphenylphosphine, tris (4-methylphenyl) phosphine, tris (4-methoxyphenyl) phosphine and tris (3-methylphenyl) phosphine. In addition, addition of an agent that accelerates the curing reaction between the epoxy resin and the curing agent is not particularly limited. For example, triethylenediamine, diaminodiphenylmethane, 1,8-diazabicyclo (5,4,0) -undecene, imidazole and derivatives thereof, which have good storage stability and moldability of the epoxy resin composition, and electrical characteristics after curing, etc. There are amine type, trifluoroborolone-amine complex, and sulfonium salt, and one kind or two or more kinds may be added to the epoxy resin and used. The addition amount can be arbitrarily determined according to the moldability of the epoxy resin composition and the physical properties of the cured product. For the purpose of increasing the glass transition temperature, amine-based, particularly imidazole-based curing accelerators are suitable.

In addition to the above materials, the encapsulating resin composition used in the present invention may contain a filler, a release agent, a coloring agent, a coupling agent, a flexibilizing agent, a flame retardant, etc., if necessary. There is. The filler is used for the purpose of reducing the thermal expansion coefficient of the epoxy molding material and for increasing the strength, and includes talc, clay, silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, glass fiber, ceramic fiber and the like. All inorganic fillers can be used.

The amount of the filler compounded is 50% by weight to 95% by weight.
However, if it is less than 50% by weight, a sufficient effect cannot be obtained for reducing the thermal expansion coefficient and improving the strength. On the other hand, if the content is more than 95% by weight, the closest packing density of the filler will be less than the content of the epoxy resin matrix, making it difficult to prepare a molding material, and the viscosity after preparation will be extremely high, resulting in moldability. descend. 7 to adjust the heat shrinkage
0 to 90% by weight is suitable.

The mold release agent facilitates mold release from the molding die, and carnauba wax, montan wax, and polyolefin wax are used alone or in combination. The addition amount is preferably 0.01 to 5% by weight of the total amount. That is, if it is less than 0.01%, the releasability is not effective, and if it exceeds 5%, the adhesiveness to the light emitting element, the light receiving element and the optical waveguide is deteriorated. It is desirable to use carbon black as the colorant. Toughened cured products,
The flexibilizer, which is blended to reduce the elastic modulus, is an amino group or epoxy group that is incompatible with the epoxy resin, a butadiene / acrylonitrile copolymer having a carboxyl group terminal, or an amino group or hydroxyl group at the terminal or side chain. , Epoxy group- and carboxyl group-modified silicone resin-based flexibilizers are used.

The above materials are blended, mixed, kneaded, pulverized and further granulated as required to obtain an epoxy resin molding material. The kneading is generally performed with a hot roll or an extruder. The optical module of the present invention can be obtained by encapsulating an optical element and a semiconductor chip on a carrier substrate with the epoxy resin composition thus obtained. Low pressure transfer molding is usually used as the manufacturing method,
In some cases, a method such as compression molding or casting can be used.

By using triphenylphosphine and its derivative as a curing accelerator, the curing temperature is set to 1
It can be reduced to 30 ° C. or less.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(Example 1) 10 parts by weight of an epoxy resin represented by Chemical formula 16 having an epoxy equivalent of 163 g / eq, 10 parts by weight of a phenol resin curing agent represented by Chemical formula 17, and 0.15 parts by weight of triphenylphosphine as a curing accelerator. , 0.4 parts by weight of antimony trioxide as a flame retardant aid, 0.15 parts by weight of epoxylane as a coupling agent, 0.1 parts by weight of montanic acid ester as a release agent, and 0.1 parts by weight of carbon black as a colorant. 1 part by weight, average particle size 2 as filler
Epoxy resin composition material was prepared by mixing 85 parts by weight of 8 mm of fused silica mixed at a ratio of 3/7. The kneading of the material was performed for 10 minutes using a biaxial hot roll (65 to 85 ° C.).

[0029]

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[0030]

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As shown in FIG. 1, a semiconductor laser, a photodiode, an optical waveguide, and an optical fiber are fixed on a flat optical waveguide substrate on which a semiconductor element is fixed so that the optical loss is minimized. Is coated with a polyimide solution obtained from 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 2,2-bis (trifluoromethyl) -4,4'-diaminodiphenyl by the potting method. did. This optical waveguide substrate is molded with a sealing resin in the above-mentioned posture, molding temperature 120 ° C., molding pressure 7MP
Transfer molding was performed under the condition of a. As a result, a resin-sealed optical module having a Bacol strength of 60 was obtained without damaging each element, the optical fiber, or the coating thereof.

Example 2 Tris (4-methylphenyl) phosphine was used instead of triphenylphosphine, and the same examination as in Example 1 was conducted. As a result, a resin-sealed optical module having a Bacol strength of 60 was obtained without damaging each element, the optical fiber, or the coating thereof.

Example 3 Tris (4-methoxyphenyl) phosphine was used instead of triphenylphosphine, and the same examination as in Example 1 was conducted. As a result, a resin-sealed optical module having a Bacol strength of 60 was obtained without damaging each element, the optical fiber, or the coating thereof.

Example 4 The same study as in Example 1 was conducted using tris (3-methylphenyl) phosphine instead of triphenylphosphine. As a result, a resin-sealed optical module having a Bacol strength of 60 was obtained without damaging each element, the optical fiber or the coating thereof.

Example 5 Tris (2,6-dimethoxyphenyl) phosphine was used instead of triphenylphosphine, and the same examination as in Example 1 was conducted. As a result, a resin-sealed optical module having a Bacol strength of 65 was obtained without damaging each element, the optical fiber or the coating thereof, as in Example 1.

Example 6 Instead of the epoxy resin shown in Chemical formula 18 of Example 1, an epoxy equivalent of 176 g / eq of Chemical formula 1 was used.
The same examination as in Example 1 was conducted using the epoxy resin shown in FIG. As a result, a resin-sealed optical module having a Bacol strength of 60 was obtained without damaging each element, the optical fiber, or the coating thereof.

[0037]

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[0038]

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(Example 7) Instead of the epoxy resin shown in Chemical formula 20 in Example 1, epoxy equivalent 176 g / eq.
For the epoxy resin shown in Example 1, tris (2,6-dimethoxyphenyl) phosphine was used instead of triphenylphosphine, and the same examination as in Example 1 was conducted. As a result, a resin-sealed optical module having a Bacol strength of 65 was obtained without damaging each element, the optical fiber, or the coating thereof.

[0040]

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[0041]

[Chemical 21]

(Comparative Example 1) Instead of the epoxy resin shown in Chemical formula 22 in Example 1, an epoxy equivalent of 195 g / eq.
The epoxy resin shown in Chemical formula 3 is used instead of the phenol resin curing agent shown in Chemical formula 24,
Further, the same examination as in Example 1 was conducted without adding triphenylphosphine. As a result, the curing was insufficient and the Bacol strength was 0.

[0043]

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[0044]

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[0045]

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[0046]

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[0047]

By using the epoxy resin composition of the present invention, it is possible to seal at 130 to 100 ° C., and it is possible to greatly reduce the damage of the optical element and the optical fiber in the optical module, and its industrial value. Is big.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical module according to the present invention.

[Explanation of symbols]

1 ... Optical fiber, 2 ... Fiber block, 3 ... Sealing material, 4 ... Transparent precoat material, 5 ... Laser diode,
6 ... Waveguide substrate, 7 ... Base substrate.

Claims (3)

[Claims] 1. An optical module in which a light emitting element, a light receiving element, an optical waveguide, and an optical fiber are arranged so as to be optically coupled to each other, after precoating the optical path with a light transmitting resin,
An optical module, wherein resin encapsulation molding is performed at a temperature of 130 ° C. or lower and 100 ° C. or higher. 2. An epoxy resin represented by Chemical Formula ₁ , a curing agent represented by Chemical Formula 2 and a chemical formula 3 (wherein X ₁ , X ₂ , and X ₃ are organic groups having 1 or more carbon atoms, hydrogen atoms, hydroxyl groups, halogen atoms). Represents an atom or an atomic group selected from among X ₁ , X ₂ , X ₃
May be the same as or different from each other) and the silica filler may be added in an amount of 50 to 9 as an essential component.
Contains 5% by weight, and resin encapsulation molding is below 130 ° C 10
The optical module according to claim 1, which is performed at a temperature of 0 ° C. or higher. Embedded image Embedded image Embedded image 3. An epoxy resin represented by the chemical formula 4, a curing agent represented by the chemical formula 5 and a curing accelerator represented by the general formula 6 as essential components, containing 50 to 95% by weight of a silica filler,
The optical module according to claim 1, wherein the resin sealing molding is performed at a temperature of 130 ° C. or lower and 100 ° C. or higher. Embedded image Embedded image [Chemical 6]